Kiln.



4 KILN.

APPLICATION FILED APR. 30, 1907.

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FIG. 3

WITNESSES.

H. w. CROFT & 0. M. REIF.

KILN. APPLIGATIQWN FILED APR. 30,1907.

Patented Sept. 29, 1908.

2 SHEETS-SHEET 2.

FIG.4"

INVENTO QZSW I l I WITNESSES. j R WW WJZ UNITED STATES PATENT OFFICE.

HARRY W. CROFT, OFPITTSBURG, AND OTTO M. REIF, OF ALLEGHENY, PENNSYLVANIA.

KILN.

Specification of Letters Patent.

Patented Sept. 29, 1908.

Application filed. April 30, 1907. Serial No. 371,056.

clare the following to be a full, clear, and exact description thereof- This invention relates to kilns such as used for burning brick, refractory blocks and the like.

The object of the invention is to provide a construction and arrangement whereby the chilling of the kiln duringfire cleaning and the removalof ashes is prevented, and whereby fuel is economized and the time of burning the contents reduced.

One form. of brick and similar kilns is,

heated by means of fire boxes provided in the walls of the kiln. Heretofore these fire boxes have generally been. provided with grates on which the coal or other fuel 'is burned, said grates being supplied with fuel through a firing door, and in breaking up and cleaning the fire the doors remain open for considerable periods. The consequence is that cold air rushes inover the fire and into the kiln and-if the fireman is slow or negligent the kiln is liable to become chilled to such an extent that it requires a long time to again get it back to its temperature, and a large part of the new fuel is consumed in overcoming the chilling efiect of the cold-air admitted at fire door. Hence, it takes much longer to burn the brick or other -contents of the kiln than should be necessary and also greatly increases the amount of fuel consumed.

The object of this invention is to provide a construction and arrangement for heating such kilns whereby there is no liability of chilling the same when supplying fuel or cleaning the fire and, furthermore, to provide an arrangement whereby the waste heat from the kiln may be utilized for the purpose of increasing the combustibility. of the fuel.

The invention consists, generally stated, in providing in or at the walls of the kiln fire boxes constructed upon the principle of gas roducers, said fire boxes having no grates but having the fuel supported directly'on the walls and floor thereof with a large body of green fuel above the same and a sealed fuel supply opening at the top and also a sealed kiln.

ash removing opening at thebottom. With this arrangement the fire is. only a smoldering one at the bottom of the large mass of fuel, the products of combustion passing up .through the fuel and robbing the latter of carbon and entering the kiln where the combustion takes place. Consequently the supplying of additional fuel or the removal of ashes from the bottom does not open a passage for the cold air into the kiln so as to chill the latter.

The invention comprises also a blast arrangement for the fire box so arranged that the air is conducted in fines formed in the masonry adjacent to the waste heat or smoke flues, thus absorbing the waste heat to raise the temperature of the air used in the blast in order to increase the heating capacity.

In the accompanying drawings, Figure 1 is in part an elevation and in part a vertical section through a kiln constructed according to our invention; Fig. 2 is a horizontal section taken in part on the line 22, Fig. 1, and in part on the line 2 -2 Fig. 1; Fig. 3 is anoutside view of a portion of the kiln; and Fig. 4 is a vertical section on the line 44, Flg. 2.

The kiln shown comprises a circular chamber 1 inclosed by the walls 2 and having an arched roof 3, the latter being provided with suitable vents 4. Underneath the fioor 5 are a series of horizontal smoke fines 6 communieating with the chamber of'the kiln by means of ports 7 throughthe floor of the kiln. The smoke flues 6 preferably are arranged radially as shown and have their inner ends communicating at 8 with the central pit 9 from which leads the main smoke flue 10 which runs to the stack. The kiln is provided with one or more doors through which the brick or other material is removed and placed in the The kiln so far described is old.

The kiln is heated by means of a series of fire boxes 14 formed either in the walls of the kiln or immediately outside the walls, referably somewhat below the floor level as s own. These fire boxes are arranged in the spaces between the outer ends of the smoke fines 6 as shown. Said fire boxes have a sloping rear wall 15 and floor 16. These fire boxes have no grates, but the fuel, such as the coal, is supported directly on the sloping wall and floor, said fuel being supplied through openings 17 arranged to be tightly closed or sealed by a door 18. These openings also serve as poke holes. At the bottom each fire box is provided with a suitable sealed opening for the removal of ashes, which may be a door if desired, but which preferably is a water seal as shown, the same comprising a wall 19 projecting downwardly into the basin formed by the floor 16, rear wall 15, and sloping wall 20 of the firing pit, and which basin contains water extending above the lower end of the wall 19 to form a water seal but permitting the removal of ashes.

The fire box opens directly into the kiln chamber 1 so that the products of combustion of the fire box pass up into the kiln chamber and the waste gases are drawn off through the ports 7 into the smoke flues 6. In order to maintain combustion in fire boxes constructed as shown, and at a high heat, and to control or regulate the rate of combustion, it is necessary to provide a blast. This is supplied through a pipe 22 and in order to increase the efficiency of the blast the air is first heated, this being efiected by the waste heat of the kiln, being accomplished by providing air fiues 23 in the masonry, said air 'fiues entering at 24 and extending inwardly toward the center of the kiln adjacent to one of the smoke fiues 6 and then turning back and extending outwardly as at 25 adjacent to another smoke fiue 6. The outer end of the arm 25 of the "flue 23 is closed as by a door 26 and communicates with the pipe 22 leading to the fire box. The blast or air pressure may be supplied in any suitable way. As shown it is supplied by an injector 27 which is in the form of a steam or air pipe 28, coming through the off-set portion 29 of the wall and being provided with suitable control valves 30. The steam or air pressure may be generated in any suitable way.

In the use of the kiln described the fuel, such as coal, is supplied through the opening 17 and practically entirely fills the fire box. When in operation the fuel supply door 18 is kept closed and a blast supplied at the bottom of the fire box, in the manner of operating ordinary gas producers. The coal is ignited only at the bottom of the large mass.

The products of combustion pass up through the mass of coal and the gases are burned at the point of entrance into the kiln. The burned gases circulate through the kiln and are drawn off through the ports 7 and fiues 6 i to the stack. The proper degree of combustion is maintained by regulating the air blast. When it becomes necessary to supply fuel the blast may be shut oif or slacked sufficiently to prevent blowing out of charging hole and the fuel is supplied through the door 18. The ashes are removed through the water seal in the basin 17 without shutting off the blast. The result is that there is practically no interruption to the continuous supply of 'fiame and heat in the kiln chamber, this not being materially reduced while re-firing or cleaning. Furthermore, no opportunity is given for a rush of cold air into the kiln either when firing or removing the ashes. The air blast utilizes the waste heat from the furnace in order to increase its calorific properties. The result is that the kiln is operated. much more economically than with old formsaml the time required for burning a given supply of brick or blocks is considerably reduced.

What we claim is:

1. A kiln comprising a chamber provided with a smoke outlet, fire boxes connected to said chamber and provided with sealed feed openings, said fire boxes having fuel supporting walls and floor, horizontal smoke ilues underneath the floor of said chamber, and air supply pipes located adjacent to said smoke flues and connected to the lire boxes.

2. A kiln comprising a chamber provided underneath its floor with horizontal smoke fines, fire boxes connected to said chamber and arranged to support the fuel directly on their walls and bottom, said fire boxes being provided with sealed feed openings and ash removing openings, and air supply pipes arranged underneath the floor adjacent to the smoke llues and leading to the fire boxes.

3. A kiln comprising a circular chamber provided umlerneath its floor with radially arranged smoke fines colnmunicating with the chamber, fire boxes connected to said chamber and communicating therewith and supporting the fuel directly on their walls and bottoms and having sealed feed openings, and air supply pipes located. umlerneath the floor of the chamber adjacent to the smoke fines and communicating with the bottoms of the fire boxes.

4. A kiln comprising a chamber provided with horizontal smoke ilues underneath its floor, fire boxes connected to said chamber and provided with sealed feed. openings and ash removing openings, said fire boxes being constructed to support the fuel directly on their walls and bottoms, air supply flues under the fioor of the chamber adjacent to the smoke fiues and communicating with the bottoms of the fire boxes, and an injector for producing a blast in said air flues.

5. A kiln comprising a circular chamber provided underneath its floor with radially arranged smoke fines which comnnlnicate with the chamber, fire boxes communicating with the chamber, and air supply means for said fire boxes comprising .flues extending inwardly underneath the floor adjacent to one smoke flue and then turning and extending outwardly adjacent to another smoke fine and communicating with a fire box, and means for producing a blast in saidv air lines.

6. A kiln comprising a circular chamber ing openings and ash removing openings, air

W. CROFT and OTTo M. REIF have hereunto set our hands.

HARRY W. CROFT. OTTO M. REIF.

Witnesses:

R. H. YOUNGMAN, S. O. WALKER. 

